Method of purifying stannic chlorid.



PATENTED JAN. 21, 1903.

E. A. SPERRY. METHOD OF PURIFYINQSTANNIG OHLORID.

APPLICATION FILED JAN. 27, 1906.

riars a ELMER A. SPERRY, OF BROOKLYN, NEW YORK, ASSIGNOR TO CHEMICAL REDUCTION COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

METHOD OF PURIFYING STANNIC CHLORID.

Specification. of Letters Patent.

Patented Jan. 21, 1908.

Application filed January 27, 1906 Serial No. 298.254.

To all whom it may concern:

Be it known that I, ELMER A. Srnam', a citizen of the United States, residing at Brooklyn, in the county of: and State in case the reagents are free from water, or

if, as is usually the case, some moisture is present the corresponding amount of hydrated stannic chlorid will be formed. This hydrated chlorid is, however, liquid at tern peratures exceeding 80 O, is capable of dissolving chlorin, sublimes freely in acurrent of chlorin or stannic chlorid vapor, and acts in general in a manner closely analogous to the anhydrous chlorid. The term stannic chlorid is employed herein as indicating either the anhydrous or hydrated salt or any mixture of these.

For a full understanding of my invention reference is made to the accompanying drawings showing in side elevation an apparatus capable of carrying out my method.

1 represents a still of any preferred construction, illustrated as a cylindrical vessel having a jacket 2 with steam and drip con nections 3, 4, a charging aperture 5 having a; suitable closure, and a draw-off tube 6, the latter extending to a point near the bottom of the vessel. The lining of the still may be of sheet lead or other light construction, in which case provision is made for equalizeing the pressure; this is conveniently eli'ected by a pressure regulator comprising a chamber '7', a pipe 8 extending from a point above the bottom thereof to a point near. the bottom of v the still, and a pipe 9 extending upwardly from a point within the chamber below the upper end of the pipe 8. end of the pipe 9 is sealed, preferably by an anhydrous liquid stannic chlorid or strong sulfuric acid. indicated it). lihen the The lower open 5 vapor pressure in the still 1 isabove that of the atmosphere the liquid 10 will stand at a corresponding level in the tube 9; when, however, by reason of condensation in the still the vapor pressure falls, air is freely admitted to the interior through the liquid 10, thereby avoiding the possibility of a collapse or rupture of the still lining.

The vapor pipe 11 extends upwardly to a considerable height and is provided with a jacket 12, to which either steanror cold water may b admitted, the steam connection being indicated at 8 and the cold water connection at 13. The vapor pipe 11 leads to a con denser 14 having a water jacket 15 and a draw-oil 16. A vapor pipe 17 leads from the condenser preferably to a reaction vessel in which chlorin may be caused to react upon a tin-bearing material.

in the operation of the apparatus shown the still is supplied with stannic chlorid containingchlorin andheat is applied to eXpel the chlorin together with such proportion of stannic chlorid as maybe carried by it. he liquid in the still is preferably brought rapidlynearly or quite to the boiling point. The

vapor pipe 11 is cooled by means of water adinitted through pipe 13 and acts as a reflux condenser to return to the body of liquid in the still 1 a considerable roportion of' the vaporized stannic chlori The expelled chlorin passes through the condenser 14 and pipe 17 to a reaction vessel where it is combined with tin as above described. When freed from chlorin the liquid in still 1 is fully the supply of cold water to the jacket 12 is cut off, and steam is admitted thereto through pipeS; thereupon the pipe 11 ceases to act as rei'iux condenser, but serves as a heater for .thestannic chlorid vapors which are conveyed to the condenser 14 and therein condensed, the purified liquid. chlorid being drawn oil at 16. in case it should be unnecessary to distil the entire body of chlorin from liquid in th e vessel 1, it may be readily withdrawn therefrom. through (lY3.WOlT (l, by means of air pressure applied through. the

' pipe 1).

When anhydrous stannic chlorid containing free chlorin is heated, both chlorin and anhydrous chlorid are driven oil", the proportion of chlorin in the vapors gradually decreasing as the heating; is continued: if these mixed vapors be cooled the stannic v method is foundin practice to require relatively large apparatus and to involve the re-handling of a uantity of the stannic chlorid which may e several percent. of the uantity in the still, the reason being that t cheating is somewhat prolonged, and dur ing the entire eriod the uncondensed vapors of stannic ch orid are returning with the chlorin to the apparatus for producing the impure chlorid. According to. the present invention the stannic chlorid containing free chlorin is heated to such temperature that the chlorin is very rapidly expelled, the preferred temperature being nearly or quite at the boiling point of the chlorinated liquid. Under these conditions stannic chlorid is freely vaporized, the vapors are condensed as far as possible by eflicient coolin means, and

the condensed liquid is returne to the still. Under these conditions of operation it is found that the escape of uncondensed stannic chlorid, instead of being increased by the use of a higher temperature is actuall decreased, the escape of stannic OhlOI'ld as chlorin and stannic chlorid, an

vapor being in fact reduced-nearly in roportion to the reduction in the time o treatment. The improvement results therefore notonly in an important saving of time, but

in a larger immediate recovery of the purified chlorid.

I claim: 1. In a method of plurifying stannic chlorid fi'onr chlori t e improvement which'consists in hea ng the liquld to expel cooling the vapors to separate stannic chlorid there- 2. In a method of purifying stannic chlorid from chlorin, the improvement which consists in heating the liquid to expel chlorin and stannic chlorid, cooling the vapors to separate stannic chlorid therefrom, and returning the separated stannic chlorid to th body of the liquid.

3. In a method of purifying stannic chlorid from chlorin, the .im rovement which consists in heating the liqui substantially to boiling, thereby expelling chlorin and stannic chlorid, cooling the vapors to separate stannic chlorid, returning the separated stannic chlorid to the body 'of liquid, and continuing the operation until the chlorin is substantially expelled from the body of stannic chlorid.

4. The method of purifying stannic chlorid which consists in heating the liquid to expel chlorin and stannic chlorid, cooling the vapors to separate stannic chlorid therefrom, then distilling the chlorin-free stannic chlorid, and finally condensing the same.

5. In a method of purifying stannic chlorid from chlorin, the improvement which consists in expelling ch orin from the liquid, separating stanmc chlorid from the gaseous ch orin, returning the se arated stannic chlorid to the body oi." the iquid, and continuing the operation until the chlorin is substantially expelled from the body of stannic chlorid.

In testimonywhereof, I aflix my signature in presence of two witnesses.

ELMER A. SPERRY.

Witnesses:

L. A; WELLES, JOHN A. FRY. 

